Reese Witherspoon's youngest child is officially a preteen — and she celebrated by sharing a rare photo of her lookalike son.

Reese Witherspoon had a sweet birthday tribute for 12-year-old son Tennessee—whom she shares with ex Jim Toth—thanking him for making her "laugh everyday."

Reese Witherspoon shared a sentimental birthday tribute to her youngest son Tennessee James, whom she shares with ex-husband Jim Toth, on Instagram on Sept. 27. Tennessee's siblings, Ava and Deacon Phillippe,

Legally Blonde star Reese Witherspoon is a mom of three, sharing Ava and Deacon with ex Ryan Philippe, and her youngest son Tennessee with ex Jim Toth

Reese Witherspoon is proudly celebrating her youngest son Tennessee’s birthday with a special message. “Happy 12th Birthday to my wonderful son, Tenn! ,” Witherspoon, 48, gushed via Instagram on Friday,

Reese Witherspoon is proudly celebrating her youngest son Tennessee's birthday with a special message. "Happy 12th Birthday to my wonderful son, Tenn! 💙," Witherspoon, 48, gushed via Instagram on Friday,

Blonde hair and bright blue eyes aren’t the only things Reese Witherspoon passed down to her preteen son Tennessee “Tenn.” The Legally Blonde alum shared a new picture with her newly minted 12-year-old and revealed one big way her youngest child,

It's a big day for Reese Witherspoon's youngest son, Tennessee, who celebrated turning 12 years old. Of course, Witherspoon posted a sweet message to commemorate the milestone—a

Reese Witherspoon's baby boy is all grown up! The Legally Blonde actress' youngest son, Tennessee James Toth, has officially marked his final year before he reaches his teens. His proud mother marked the occasion with a rare photo of her youngest child,